1. Field of the Invention
The present invention relates to a photographic camera and more particularly, to a camera which is suitable for recording a number of negative images on roll film, the negative images then being recorded on a magnetic sheet which is put on a player for reproducing the images on a CRT screen.
2. Description of the Prior Art
Electronic still cameras which have been recently developed use a magnetic sheet standardized as a still video floppy to be disposed therein in place of conventional photosensitive film having at least an emulsion layer being made of silver halide. The optical image formed by the taking lens is converted into video signals so as to be recorded on the magnetic sheet in the camera. The magnetic sheet thus provided may be transferred to reproducing equipment in order to view the images on a CRT screen. The standardized magnetic sheet includes 50 available tracks, each one being assigned to a file image.
Such electronic image recording and reproducing systems as mentioned above, having a great difference from the conventional photosensitive film cameras, can not only eliminate darkroom film processing but also permit viewing of the photographed images instantaneously on general TV screens with ease, and furthermore permit displaying a successive action sequence of still images.
The above-mentioned electronic still camera is, however, prohibited, in view of manufacturing cost and weight, from using high quality image pick-up tubes or solid state imaging. A particular problem for the practical application of the electronic still cameras has been the improvement of image quality and resolution.
As a way of solving the problem, it has been proposed to use conventional silver halide photosensitive films and conventional still cameras in order to obtain good quality and high resolution images. In that way, the photographic film on which a number of latent images are formed may be processed at the photofinishing laboratory, professionally, using high performance image pick-up equipment. By this method, negative images are converted into video signals for recording onto a magnetic sheet. The magnetic sheet thus provided in the photofinishing laboratory may be transferred to reproducing apparatus so as to display the images on a TV screen. By such a method, images on the photographic film can be easily recorded on a standard magnetic sheet having the same format as used in electronic still cameras, and the images can be reproduced by use of the reproducing apparatus of the electronic still camera system.
The above-mentioned electronic image reproducing system has a particular feature that a series of still images can be successively reproduced and displayed on a TV screen by successively shifting the magnetic head so as to regenerate signals recorded on tracks on the magnetic sheet which is continuously rotated at high speed. Corresponding to the shift of the magnetic head, different still images are displayed on the TV screen one after another.
Therefore, when a series of still pictures on the photographic film are action sequences which can be taken by repeatedly firing the shutter and winding automatically at a firing rate between, for example, one and six frames per second, it is possible to reproduce the action in either slow motion mode or stop motion mode for action analysis by changing the shifting interval of the magnetic head.
However, for such a changing operation, it is necessary to find the first one of the series of successive pictures while viewing the reproduced images on the TV screen. A further requirement is to return the interval to an ordinal one. These inconveniences make usage troublesome.
These changing operations may be eliminated by recording detectable action signals on the respective tracks of the magnetic sheet. The action signals indicate that the image to be reproduced is a part of a series of successive images and further indicate the firing rate at which the picture corresponding to the image to be reproduced has been photographed. The respective signals are employed to automatically change the shifting rate of the magnetic head when reproducing the images. However, it is hard for processing dealers to judge whether and on which tracks such signals should be recorded when editing the magnetic sheet from the film on which a number of pictures are formed.
There has recently been proposed 35 mm compact cameras of the type known as prewinding cameras using the 135 size roll films, which are adapted to wind entirely the loaded roll film around the take-up spool before exposure. In such cameras, the roll film is automatically rewound by one frame every exposure. The significant feature of such cameras is to expose the roll film in the reverse order to the frame number, i.e. the last frame first. Consequently, when the roll film having frames exposed in the reverse order of frame number is supplied to the processing dealer for transfer to a magnetic sheet on which images formed on the roll film, after development, are magnetically recorded in such a way as mentioned above, the images are recorded in the reverse order of exposure, i.e. in the order of frame number on the magnetic sheet. As a result, the images will be reproduced in the reverse order of exposure. As described above, a particular problem is that the magnetic sheet from the film provided by the prewinding camera cannot reproduce the picture images in order of time sequence.